1. In all these sentences the emphasis is on We, which implies that it is Allah Who has revealed this and none else; therefore: You should not treat these instructions lightly like the word of an ordinary preacher. You should note it well that these have been sent down by One Who controls your lives and destinies and from Whom you can never escape even after your death.
The second sentence emphasizes that the instructions sent down in this Surah are not of the nature of advice which you may accept or reject at will. These are mandatory commandments which must be obeyed. If you are a believer and a true Muslim, you are obliged to act upon them.
The third sentence states that the instructions given in this Surah are free from any ambiguity and are couched in clear and plain words. Therefore, you cannot put up the excuse that you could not act upon them as you did not understand them.
This is the preamble of this blessed message after which the specific commandments follow. The cone of the preamble itself indicates the great importance which Allah has attached to the commandments contained in Surah An- Noor. The preamble of no other Surah containing commandments is so forceful as this.